1. Field of the Invention
The present invention generally relates to a woven fabric which is designed for use in a papermaking, cellulose or board manufacturing machine and more particularly to a double layer papermaking fabric.
2. Description of the Prior Art
Woven fabrics of single and double layer constructions are used in the various sections of a papermaking, cellulose, board or other similar machine. Frequently, double layer fabrics have two layers of cross machine direction (CMD) yarns which are interconnected by a system of machine direction (MD) yarns. One type of double layer fabric which is useful in a dryer section is shown in FIG. 1. This fabric is characterized by a weave in which each MD yarn in succession binds between a first pair of CMD yarns, above a second pair, between a third pair and beneath a fourth pair before the procedure is repeated. This MD weave pattern generally produces a yarn having a diagonal section that passes between CMD layers and is often referred to as an "N" weave.
The structure of standard double layer fabrics results in fabrics which are less stable in the MD since the MD yarns weave into the construction with fewer interlacings of the CMD yarns and provide little crimp interchange between the MD and CMD yarns. As a result, the double layer fabric's ability to withstand distortion during use is decreased. A common method of enhancing fabric stability is the addition of post weaving treatments or resins. However, these processes are generally messy, time consuming and expensive.
Accordingly, there is a need for a double layer papermaking fabric which provides greater stability without requiring finishing processes to achieve such stability.